Conventionally, systems for measuring one or more spatial positions of one or more corresponding wireless communication devices, for example smart phones, within a given region are known. These systems operate, for example, by monitoring received strength of a wireless signal transmitted from a wireless device at a plurality of receivers disposed at mutually different spatial positions in respect of a given region; by trigonometric computations derived from data indicative of spatial positions of the plurality of receivers and their respective received signal strength, a spatial position of the wireless device within the given region can be determined. Alternatively, there are provided a plurality of transmitting devices disposed at mutually different locations within a region, wherein a wireless device is operable to receive wireless signals transmitted from the plurality of transmitting devices; by trigonometric computations derived from data indicative of spatial positions of the plurality of transmitting devices and their respective received signal strength at the wireless device, a spatial position of the wireless device within the region can be determined.
Such position measurement of wireless devices such as smart phones has been proposed. Smart phones are operable to transmit their MAC addresses which are received by a plurality of receivers disposed at mutually different spatial positions in respect of a given region. This enables the smart phones, from their MAC addresses, to be spatially tracked within the given region. Network interfaces in wireless devices have unique device codes called “media access control address”, namely abbreviated to aforementioned “MAC address”. MAC addresses are used as a network address for most IEEE802 network technologies, including Ethernet, WLAN and Bluetooth; “Ethernet”, “WLAN” and “Bluetooth” are trademarks. This means that there is a unique MAC address in a given phone for cellular radio, Wi-Fi and Bluetooth (BT), for example.
It is known to employ hashing of MAC addresses in a context of positioning systems for UUID (unique user ID) generation in commercial products.
Referring to FIG. 1, a consumer 102 with his/her phone, which has Wi-Fi/BT installed and activated thereupon, is, for example, walking in a shopping mall. The phone continuously searches for available network connections by probing a wireless environment of the shopping mall in order to find a network that it is capable of joining. This involves sending a MAC address.
Sensors 100 receive one or more probes sent from the phone, thereby measuring signal strength and similar, and sending corresponding data to a server 108. Now, the server 108 is able to compute, as described in the foregoing, an approximate location of each MAC address, namely a spatial position of each consumer within the shopping mall.
An essential problem arising in practice in relation to FIG. 1 concerns privacy. The MAC address is a unique identifier that can be associated with a given consumer. Tracking individual consumers is undesirable from a privacy perspective. There might be, or might come, legislation related to privacy which limits storing of unique identifiers of any kind of related data without consent of a given user. In addition, there might be, or might come, legislation which prohibits collection of user identifications, namely “id's”, even with the consent of the user. Moreover, system customers are also wary of consumer privacy.